1. Field of the Invention
The present invention relates to an Internet printing method, a system thereof, a proxy unit and a print server for transmitting printing data to a printer through the firewall of an organization from a client on the Internet and printing to that printer, and more particularly to an Internet printing method, a system thereof, a proxy system and a print server for printing data by a printer at a remote area under a firewall using IPP (Internet Printing Protocol) from outside a firewall.
2. Description of the Related Art
Today as the Internet spreads, methods for communicating by connecting various equipment and networks via the Internet are in use. As a method to share a printer in this inter-network, the IETF standardized IPP (Internet Printing Protocol) in RFC 2565-9, RFC 2616 and RFC 2639. IPP is described in detail in Chapter 18, “Sharing files and printers” of “TCP/IP Protocol and Service Guide”, published by Nikkei BP Soft Press Co.
FIG. 37, FIG. 38 and FIG. 39 are diagrams depicting conventional Internet printing models. Internet printing by IPP has functions for the user to install, use and monitor a printer via an inter-network. By this, the client can access a printer via the Internet as if the printer were directly connected to a local area network (LAN) of a company.
In other words, the user can install a printer using a Web browser and additional Wizard software of the printer by IPP, and at this time the user can specify a URL (Uniform Resource Locator) or an IP (Internet Protocol) address instead of a UNC (Universal Naming Convention) path of a printer. Also output can be directly sent to a URL using the printer interface when a printing request is sent after the printer is installed.
As FIG. 37 shows, when an IPP client 110 and an IPP server (printer) 112 are directly connected with the Internet 100, printing by the printer 112 at a remote area is possible using IPP.
Also as FIG. 38 shows, a firewall 114 is disposed between an intranet and the Internet to protect security against network crimes which occur as the Internet develops.
A setting policy of the simplest and most typical firewall 114 is permitting all connections from inside the firewall to the outside, and permitting only connections to the public server with a restricted protocol for connections from outside the firewall to inside the firewall. Here the network outside the firewall is defined as an “extranet” and the network inside the firewall as an “intranet”.
As FIG. 38 shows, the client 110 in the organization can print out to the printer 112, which is directly connected to the Internet 100, using IPP by setting a server (proxy server) to insure security (firewall).
However, as FIG. 39 shows, the client 110 cannot execute a print out to the printer 112 under the firewall 116, since an IPP packet cannot pass due to the protection of the firewall 116.
On the other hand, FIG. 39 shows a request for the client 110 to execute a print out to the printer 112 under the firewall 116 via the Internet 100 using IPP. This is an example when a member of a company prints out to the printer 112 under the firewall 116 of the company from home or outside the company via the Internet 100, or when an individual outside the company executes a print out to the printer 112 under the firewall 116 of the company via the Internet 100 at the request of the company.
As a method of printing by circumventing the firewall, it is proposed that print data is attached to an electronic mail, is converted to SMTP (Simple Mail Transfer Protocol), and is printed (e.g. Japanese Patent Laid-Open No. H10-187370).
With this method of using an electronic mail, however, the following problem occurs. This method is inappropriate for printing a large volume of print data since a mail server may restrict the mail size. Also accurate printing is not guaranteed with electronic mail. Also the printer status and printing status cannot be acquired.